1290891239820 has 576 divisors, whose sum is σ = 5138276290560. Its totient is φ = 266565551616.

The previous prime is 1290891239797. The next prime is 1290891239837. The reversal of 1290891239820 is 289321980921.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 16127137 + ... + 16206983.

It is an arithmetic number, because the mean of its divisors is an integer number (8920618560).

Almost surely, 2^{1290891239820} is an apocalyptic number.

1290891239820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1290891239820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2569138145280).

1290891239820 is an abundant number, since it is smaller than the sum of its proper divisors (3847385050740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1290891239820 is a wasteful number, since it uses less digits than its factorization.

1290891239820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79939 (or 79924 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 1290891239820 in words is "one trillion, two hundred ninety billion, eight hundred ninety-one million, two hundred thirty-nine thousand, eight hundred twenty".